ROS与QT语言入门教程-显示ROS发布的视频消息
ROS与QT语言入门教程-显示ROS发布的视频消息
说明
- 实现显示ROS发布的视频消息
确定PC端的USB摄像头的正常使用
roslaunch usb_cam usb_cam-test.launch
步骤
- 创建ROS-QT-GUI模板 mul_t
catkin_create_qt_pkg mul_t
- 修改界面gui
main_window.ui
文件:拖入一个标签控件,将对象名改为label_camera
- 修改main_window.hpp
#include <QtGui/QMainWindow>
#include "ui_main_window.h"
#include "qnode.hpp"
#include <QImage>
#include <QMutex>
namespace mul_t {
class MainWindow : public QMainWindow {
Q_OBJECT
...
public Q_SLOTS:
...
void updateLogcamera();
void displayCamera(const QImage& image);
private:
Ui::MainWindowDesign ui;
QNode qnode;
QImage qimage_;
mutable QMutex qimage_mutex_;
};
} // namespace mul_t
#endif // mul_t_MAIN_WINDOW_H
- 修改qnode.hpp文件
//添加头文件
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <image_transport/image_transport.h>
#include <cv_bridge/cv_bridge.h>
#include <QImage>
...
public:
void myCallback_img(const sensor_msgs::ImageConstPtr& msg);//camera callback function
QImage image;
Q_SIGNALS:
void loggingCamera();//发出设置相机图片信号
private:
int init_argc;
char** init_argv;
ros::Publisher chatter_publisher;
QStringListModel logging_model;
image_transport::Subscriber image_sub;
cv::Mat img;
修改main_window.cpp
/*********************
** Logging
**********************/
QObject::connect(&qnode,SIGNAL(loggingCamera()),this,SLOT(updateLogcamera()));
void MainWindow::displayCamera(const QImage &image)
{
qimage_mutex_.lock();
qimage_ = image.copy();
ui.label_camera->setPixmap(QPixmap::fromImage(qimage_));
ui.label_camera->resize(ui.label_camera->pixmap()->size());
qimage_mutex_.unlock();
}
void MainWindow::updateLogcamera()
{
displayCamera(qnode.image);
}
- 修改qnode.cpp:
#include "sensor_msgs/image_encodings.h"
void QNode::myCallback_img(const sensor_msgs::ImageConstPtr &msg)
{
try
{
cv_bridge::CvImageConstPtr cv_ptr = cv_bridge::toCvShare(msg, sensor_msgs::image_encodings::RGB8);
img = cv_ptr->image;
image = QImage(img.data,img.cols,img.rows,img.step[0],QImage::Format_RGB888);//change to QImage format
ROS_INFO("I'm setting picture in mul_t callback function!");
Q_EMIT loggingCamera();
}
catch (cv_bridge::Exception& e)
{
ROS_ERROR("Could not convert from '%s' to 'bgr8'.", msg->encoding.c_str());
}
}
运行
- 启动相机
rosrun usb_cam usb_cam_node
- 执行qt程序
参考资料
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